Four-party key.



A. P. DIXON.

FGUR-IARTY KEY.

AIwL-mA-rmx FILED JUNE 11, 1910.

1,105,629, Patented Aug.4, 1914.

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UNITED-STATES PATENT OFFICE.

AMOS DIXON, OE NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC 2 COMPANY, OE.NEIW YORK, N. Y., A CORPORATION OF ILLINOIS.

Specification of ltetters Patent.

EQULPABTY KEY.

Patented Aug. 4; 19 14.

. Application filed June 11, 1910. Serial No. 566,389.

Keys, of which t e following is in full, clear,

concise, and exact description.

Myinvention relates to an operating key forselective party line ringing and more particularly to that class of keys wherein the last key depressed remains ina partly depressed position by reason of its engagement with' a mechanical latchin' device to indicate to the operator upon w iich line the last My invention has for its object to generally improve .the form and construction of of my invention-namel such a key to insurethe most efiicient opera.- tion and provide a structure "of few and siniple parts, easily assembledand easily accessible for cleaning or repla'cement.

In carrying outmy invention I rovide a novel form of plunger b: means 0 which I am 'able to accomplish tie principal object the provision, without expensive maeh-i'mng o erations, of aconvenient mountingspace or a spring operating roller; whereby the Width of the key 's'tr ucture' is materially decreased, and a convenient and efficient means for preven't in'g thekey plun rs from' turning in their guides without t e useof extra parts such as have heretofore been used." A key plunger which has Y been 'found'. convenient fhr'the' above'purposes co 'risesge nerally two slide ieces'eonnected yi mean's of a 'oke, said yoke comprising an upper'and a owei horizontal plateand a] vertical conn'ectingsi'de' plate or'web'joi ning said upper and lower horizontal plates' The upper and lower slide members 'a're'- attached to said horizontatplates' and said horizontal-plates are adapted toeoiiperatewith a' hinged latch plate in] the manner hereinafter} described. The spring operating roller is pivotally mounted uponthe'inner face of-said vertical connecting web in such a manner that-it projects beyond the "plunger only- 'in a' longitudin'al direction'of the "key. F j

*Det'ails of m invention are-the method-of mounting the. eys upona unit' fra me with the keys individually removabletherefrom, the mounting of the springs and the manner of securing the key caps to the plunger-rods.

the drawings illustrating my invention Figure 1 1s a view in side elevation with parts broken awa of a key embodying my improvements; Fig. 2 is a detail view 'partially in section of two of the keys, one in ringing and the other in indicating position; Fig. 3 is a detail sectional view taken upon line 3-3 of Fig. 1; Fig. 4 is a detail sectional view taken upon line 44 of Fig. Zand illustrates the parts with the key in its indicating position; Fig. 5 is adetail sectional view taken upon line 5-5 of Fig. 2, and illustrates the parts with the key in the ringing position; Fig. 6 is a detail sectional view taken upon line (3-6 of Fig. 1 and illustrates a key with the parts in normal position; Fig. 7 is a perspective of the latch plate; and Fig. 8 is a perspective of the key plunger stamping forming part of my invention.

Like reference numerals are used to designate like parts through the drawings.

In the drawings, 5 designates a metal top plate which is shown as faced with hard rubber. Secured to the top plate 5 is an inverted U-shaped frame 6 upon which are mounted the operating parts of the 'key. The lower ends of the inverted U-shaped frame are connected by a frame member 7 upon which are mounted a plurality of supporting blocks 9, 8 to each of which are secured sprin contact members 9 and 10, each of said bloc (s also being adapted to receive the lower end of a key plunger as will hereinafter appear. There are illustrated inthe drawings four key plungers, this :being'the number in theparty line key ordinarily used. 'These'plungers are allalike and' a description of one will suffice for a clear un-' derstanding of the key.- As shown each of said plungers' comprises three. principal parts, an upper rod 15 exte n ding down wardly through the top plate 5 and a registering opening in the top member of the frame 6, a lower rod 17- entering a guide hole in the block 8 and an intermediate con- 'necting member or yoke joining said upper and lower rods. The connecting member or yokeis preferably made of a metal stamping and as shown in Fig. 8 is provided with an upper and a lower horizontal-plate 20and llO The upper horizontal plate 20 is provided with a reduced ortion 22 and transversely arranged shoulders 23, 23 adjacent thereto which are beveled on their under sides, said reduced portion being adapted to engage an opening in a latch plate 30 to prevent the turning of the key plunger. The lower horizontal plate 21 is provided with a projection 27 formed by turning upwardly and outwardly a portion of said lower horizontal plate. An antifriction roller 25'pivotally mounted upon the inner face of the web 16 of said yoke in the central longitudinal axis thereof is adapted to engage the spring 10 to press it into engagement with the sprin 9. p

Re erring now to the latch dplate 30, same is shown in full in Fig. 7 an is preferably stamped from a sin le piece of metal. Said plate is adapted to e secured to the legs of the U -shaped frame 6 and for this purpose is provided on its opposite ends adjacent to its lower margin with project' members 32, 32 adapted to lie flat against t e faces of the legs of said U-shaped frame and to be pivotally secured thereto. Along its upper margin said latch late 30 provided with a plurality of Us aped latch members 40, 40, the legs of which are bent over forming hook members 41, 41 which engage the upper horizontal plate 20 upon the yoke 16 when the key is pressed into its indicating osition. Vertically below the slots in' the -shaped latch members the latch plate is provided with inwardly projectin members 45, which in the operation of t e key are ada ted to be engaged by the projection 27 on 51c connecting yoke to force said latch plate outwardly. The reduced portion 22 of the upper plate 20 on the yoke 16 passes between the legs of the U-shaped members 40, 40, thus serving to prevent said plunger from turning in its operation to disengage the periphery of the roller 25 from its 00- acting spring. Near its upper margin and on one end thereof said plate is provided with an integral arm 34 extendinguat right an les to the face of the plate to w 'ch is at tafiied a laterally pro'ecting roller member 35 adapted when sai plate is in place to roject through a slottde 0 ening in the adacent leg of the U-shaped ame and engage a sprin 36 which spring controlsa plu rality 0 contacts and also acts in the o eration of the key plungers to press the atch plate into engagement with the coacting parts of the plunger member 16.

In the operation of any one of the keys r the movement of the parts will be as follows:

Assuming that the key starts from its normal osition then the first movement thereof will ring the beveled faces of the shoulders 23, 23 on the upper plate of the connecting yoke into engagement with the top portion of the hook members 41, 41 on the latch on the connect hea plate forcing said plate outwardly against the action of the spring 36 and permitting said shoulders and hook members to pass one another in the downward movement 01 the key. In its continued downward move ment to bring the roller 25 into engagement with the springv 10 the lower projection 27 yoke will engage its 00- operating rojection 45 on the latch plate 30 and w' press said latch plate outwardly a greater distance than it was forced by-the passing of the shoulders 23, 23 and the hook members 41, 41 and said latch plate in this movement will move the rin 36 to close spring contacts controlled' there y. A coiled actuating spring 50 surrounding the lower rod 17 o the plunger and hearing at its 0 posite ends against the .up er end of t e block 8 and the lower end 0 the connecting yoke will operate to move said lunger upwardly when the pressure of tiiej'finger is removed therefrom. As said key is moved upwardly and the lower projection 21 on the connecting yoke moves away from the projection 45 on the latch late, said latch 90 plate will be swung inwardly by the action of the spring 36 until the lower faces of the hook members 41, 41 engage the to face of the upper plate 21 of said yoke and lock said key plunger in its indicating position. Ordinarily the key last operated will be released from its indicating position as soon as the succeeding key moves past the indicating position in its downward movement, but in case the latching portions of one. of the keys becomes worn to such an extent that it will not release the key last in the indicating position in the first part of its move ment it will operate the etch plate to release it when the lower projection 21 on the 5 connecting yoke is brought into'engagemen: with the coacting projection 45 on the latch plate 30. j a

As hereinbefore stated the plunger rod 17 engages and slides in a hole in the guide 0 block 8, this guide block also sup orting the springs 9 and 10. As shown said block 8 is attached to the connecting bar 7 and for this purpose both the block and the bar are notched, the bar being notched on its 0 posite mar to receive the portions 0 the block ad acent to a notch provided thereon to fit over the notched portion of said bar. Each block is secured to the bar by means of a single machine screw 55, sa1d block 12o bein provided with a notch 56 to permit the (F of the screw to be sunk flush with or below the face of said block. The springs 9 and 10 are secured to one side face of the block 8 by means of machine screws 57, 57, the entire arrangement being such that any one of the plungers and blocks can be removed for replacement of any of the parts without disturbing the other lungers.

Key caps 60, 60 of hard ru her or other ioo suitable material are provided with threaded metal bushings 61, 61 adapted to engage a screw threaded portion 63 at the upper end of the plunger rod 15. A lock nut 65 is adapted to engage the lower face of each of said key caps to prevent them Working loose in the operation of the keys.

A block 70 carrying the spring 36 and its associated spring contacts is secured to the outer face of one of the legs of the U-shaped frame by means of machine screws.

An indicating key embodying the features hereinbefore set forth is not only convenient to assemble but is very compact and the simplicity of the parts enables the manufacturer to produce such a key at low cost. Moreover the arrangement of parts herein shown and described enables the user to replace any which may become broken or otherwise dama ed without dissembling the entire key. A1? of the contacts are easily accessible making the key easy to clean.

I claim 1. In an operatin key the combination with a frame work, of contact springs mounted upon saidframe work, a key plunger and a spring operating roller carried by said plunger, said plunger embracing an upper and lower rod and a connectin yoke having an upper and lower horizonta plate, and a vertical connecting webfor said plates to the inner face of which said spring op erating roller is pivotally secured.

2. In an operating key the combination with a frame work, of a swinging latch plate carried thereby, said latch plate being provided on its upper margin with notches and between its upper and lower margins with projecting members, and a plurality of reciprocating key plungers adapted to cooperate with said latch plate, each of said plungers embracing an upper and lower rod and a connecting yoke therefor having an upper and lower horizontal plate, said upper plate having a projecting portion extending through a notch in the upper margin of said latch plate and said lower plate aving a portion thereon adapted in the movement of the key plunger to engage a projection on said latch plate to swing said latch plate outwardly.

3. In a key, the combination with a framework, a swingin latch plate carried thereby, said latch p ate being provided with a notch, locking projections formed integrally with said plate, and a plunger having an integral portion cocperating both with said projections and said notch whereby said plunger may be held in a depressed position and against turning.

4. In a key, the combination with a framework, a swingin latch plate carried thereby, said latch p ate being provided with a notch, overturned projections on said plate formed of the material adjacent said notch, and'a plunger having integrally formed extensions cooperating with said overturned portions and said notch whereby said lunger is locked in a depressed position and prevented from turning.

In witness whereof, I, hereunto subscribe my name this 9th day of June A. D., 1910.. AMOS F. DIXON.

Witnesses:

MORGAN WASHBURN, Jr., IRVING MACDONALD. 

